Label-free chemical contrast is highly desirable for imaging in the life sciences as it allows non-invasive observation of biological systems and processes. Here I propose the development and application of femtosecond stimulated Raman scattering (FSRS) microscopy, a novel imaging technique whose broadband nature will enable the simultaneous imaging and quantification of multiple species in a biological sample. The primary challenge of this project will be attaining high sensitivity and chemical specificity with three-dimensional diffraction-limited spatial resolution, with the short-to-midterm goal of obtaining quantitative and chemically specific images of whole cells that reveal several to tens of different species and compartments simultaneously. Potential long-term applications for this technique include the direct monitoring of intracellular processes, lipid metabolism and drug delivery in tissues, important phenomena that are intrinsically difficult to study with established optical techniques. PUBLIC HEALTH RELEVANCE: Femtosecond stimulated Raman scattering is a novel approach to biomedical imaging. It allows the noninvasive observation of a wide variety of biological processes that are beyond the reach of currently available methods. This technique will give us the capability to directly monitor intracellular process, lipid metabolism and drug delivery in tissues, which will open many exciting possibilities for biology and medicine.